Multiple wheel combination lock

ABSTRACT

A multiple wheel combination lock having springs mounted on a pivotable actuator plate to engage and rotate the wheels in a random fashion each time the lock is opened so that the correct combination is not in view. Each wheel has numbers, letters or other indicia on its circumference which form the basis of the combination. A movable cover member is provided to cover and protect the wheels when they are not in use and to engage and disengage receiving means to lock and unlock the device.

United States Patent 11 1 Mohrhauser et a].

MULTIPLE WHEEL COMBINATION LOCK Inventors: John P. Mohrhauser, 804 Prospect St., Maplewood, NJ. 07040; Richard W. Strazza, 3 Turner Ct.,

Princeton, NJ.

[22] Filed: June 2, 1972 [21] Appl. No.: 259,260

[52] US. Cl 70/314, 70/133, 70/312, 70/315 [51] Int. Cl E05b 37/02 [58] Field of Search 70/3, 4, 5, 133,

[56] References Cited UNITED STATES PATENTS 3,677,042 7/1972 Atkinson 70/312 X 3,633,388 1/1972 Atkinson.... 70/314 X 2,136,493

11/1938 Penerich 70/312 X 3,459,016 8/1969 Atkinson 70/312 FOREIGN PATENTS OR APPLICATIONS 21,714 10 1902 Great Britain .l 70 312 Primary ExaminerMarvin A. Champion Assistant ExaminerRichard P. Tremblay Attorney-4D. C. Roylance et al.

1 1 ABSTRACT A multiple wheel combination lock having springs mounted on a pivotable actuator plate to engage and rotate the wheels in a random fashion each time the lock is opened so that the correct combination is not in view. Each wheel has numbers, letters or other indicia on its circumference which form the basis of the combination. A movable cover member is provided to cover and protect the wheels when they; are not in use and to engage and disengage receiving means to lock and unlock the device.

10 Claims, 10 Drawing Figures PATENTEUUBI 23 1975 3.766.760

SHEET 1 [1F 6 PMENTFUUCIPR IBIS SHEU S UT 6 MULTIPLE WHEEL COMBINATION LOCK This invention relates to combination locks and more particularly it relates to a multiple wheel combination lock of the type which automatically changes the wheel setting after the lock is opened so that the combination cannot be visually observed.

Combination locks having multiple wheels are well -known in the art. The multiple wheels or cylinders are exposed to view and contain numbers or colors on their circumferences to provide the basis for the combination. On dialing the various cylinders to the correct combination, the lock may be opened. However, the prior art locks of this type all expose their correct combination when they are not locked unless the cylinders are reset manually after the lock is opened. Many times the person dialing the combination will forget to reset the wheels and thus anyone seeing the lock in its open position can discover the correct combination or change it.

Locks of this type are used on luggage, lockers, safes, safety deposit boxes, trunks and doors. They are especially useful in any situation where the carrying of a key is not practicable or where the existence of a key will impair the security of the locked device.

It is an object of the present invention to overcome the limitations and drawbacks associated with the aforesaid prior art locks and to provide a new and improved multiple wheel combination lock.

Another object of the present invention is, to provide a multiple wheel combination lock which automatically changes the position of the wheels from the correct setting when the lock is opened.

Another object of the present invention is to provide a multiple wheel combination lock having a key so that the lock may be opened without divulging the combination.

Another object of the present invention is to provide a lock which is sealed against the introduction of harmful dirt into the mechanism.

It is a further object of the present invention to provide a multiple wheel combination lock whose combination can be changed when the lock is open and the proper combination set.

Qther objects, advantages and salient features of the present invention will become apparent from the following detailed description, which, taken in conjunction with the annexed drawings, discloses a preferred embodiment of the present invention.

Referring now to the drawings, which form a part of this original disclosure:

FIG. 1 is a perspective view of a lock in accordance with the principles of the present invention;

FIG. 2 is a sectional view taken along line 22 of FIG. 1 showing the lock in its closed position;

FIG. 3 is a sectional view taken along line 33 of FIG. I in elevation;

FIG. 4 is a sectional view taken along line 4-4 of FIG. 2, showing the lock in locked position;

FIG. 5 is a sectional view similar to FIG. 4, but showing the actuator plate with the correct combination dialed;

FIG. 6 is a sectional view similar to FIG. 4, but slowing the actuator plate in its position when the lock is opened;

FIG. 7 is a perspective view of the arm and the actuator plate;

FIG. 8 is a perspective view of the shaft, one clutch cylinder and one indicator wheel;

FIG. 9 is a sectional view similar to FIG. 2 but showing the lock in open or unlocked position; and 7 FIG. 10 is a sequential schematic view showing how the actuator plate moves from its position in FIG. 5 to its position in FIG. 6.

The foregoing objects are obtained by utilizing apparatus to spin the wheels each time the lock is opened. The lock consists basically of three parts. The first part is a container housing the wheels and an actuator plate. The wheels are accessible through slots in the container wall. The second part is a cover member having projections and a depending slotted arm, which member is movable along the container. In the locked position the cover member covers the wheels and prevents harmful dirt from entering the mechanism. The third part is a member having engaging means for receiving the projections. The movable cover member fits over the container with the depending arm connected thereto passing through a slot in the front wall of the container and located withinthe container adjacent an extension of the actuator plate. The actuator plate is pivotably mounted at one end within the container and has slots which receive a portion of the wheels. When the correct combination on the wheels is dialed the actuator plate pivots and aligns with aslot in the dependingarm. Since the cover member is spring biased it moves and causes the projections thereon to become disengaged from their receiving-means and opens the lock. The slot in the arm acts on a cam extension to the actuator plate and pivots the actuator plate allowing springs thereon to spin the wheels from the correct combination in a random fashion. A key passing through an auxiliary lock in the cover member can engage and pivot the ac tuator plate so that a second slot will be aligned with the'plate and allow the cover member to move to open the lock. The wheels are mounted to a shaft by clutch cylinders which allow the combination to be changed.

Referring to the drawings infurther detail, the device of the present invention is generally designated 20 as seen in FIG. 1.

The device consists generally cover member 60, locking projections 62 and locking projection clamps 63. The cover member 60 is reciprocally movable longitudinally along the container40 to cause the locking projections 62 to move into and out of engagement with the clamps 63 and thus provide the locking and unlocking functions. i

As seen in FIG. 2 container 40 is rigidly connected to a movable member 22 and receiver 64 carrying the clamps 63 is rigidly connected toa fixed member 24. For example, the movable member 22 could be a door and the fixed'member 24' could be a door jamb.

The container 40 is formed from six rectangular planar walls rigidly connected to enclose a rectangular shaped housing. The container 40 has a bottom wall 41, a front wall 42, a side wall 43, a rear wall 44, a top wall 45, and. a side wall 46 as seen in FIGS. 2 and 3.

The rearwall 44 is rigidly mounted to the movable member 22 by the use of the projections 51 and a bolt 52. Each projection is rigidly connected to the rear wall 44, is perpendicular thereto and has a threaded aperture therethrough for receiving the bolt 52. The projections fit into corresponding recesses in the movable member 22. Bolt 52 passes through a suitably formed hole in the movable member 22 and passes through the of a container 40, a

apertures in the projections as seen in FIG. 2. A similar type of rigid connection between the fixed member 24 and the receiver 64 may be used as shown in FIG. 2,

utilizing projections 53 and a bolt 54.

The front wall 42 of the container has three centrally located elongated rectangular slots 56, 57 and 58, therein.

The top wall and the bottom wall 41 each have two elongated rectangular slots running from their left side to substantially the middle of the wall, each slot being spaced from the wall edge by approximately one third the width of the wall. The slots in the top wall 45 are designated 71 and those in the bottom wall 41 are designated 72, as shown in FIG. 4.

The side wall 46 has a centrally located circular aperture 75 therein. Similarly, the side wall 43 has a centrally located circular aperture 76 therein. Additionally, two circular apertures 77 and 78 are located in the side wall 43, each spaced slightly from the rear edge of the side wall 43 and spaced from the side edges as seen in FIG. 3. Inverted T-shaped slots are provided at the top and bottom edge of the side wall 43, in alignment with the slots 71 and 72, for purposes to be described hereinafter. An aperture 83 is also located in the side' wall 43 adjacent one corner as shown in FIG. 3.

The back wall 44 has two elongated rectangular slots 84 and 85 located therein as seen in FIG. 2. Slot 84 is adjacent one end of wall 44 and slot 85 is adjacent the other end. These slots provide passages through which the various parts of the locking device can be inserted into the container and through which a screwdriver can be placed to mount the various parts in their proper places within the container.

Mounted within the container 40 are the shaft and the actuator plate 92. The shaft 90 as seen in FIG. 2 is an elongated cylindrical rod having an increased diameter end portion 91 with a length equal to about onefifth the overall length of the shaft 90. The end 91 of the shaft 90 is rotatably supported in container 40 by means of the circular aperture 76in the side wall 43 and a support 93 located adjacent side wall 46 in the container 40. The support 93 is formed from two parallel plates 94 and 95 which are connected at their edges to the walls of the container. The plates 94 and 95 are spaced by a distance equal to at least the width of the slot 85 on the rear wall 44 and have central apertures 96, 97 respectively, aligned with the aperture 75, for receiving the shaft portion-91. The plates 94 and 95 also contain apertures 86 and 87, respectively, offset from the central apertures 96 and 97.

The opposite or smaller diameter end of the shaft90 passes through the central aperture76 in the side wall 43 and contains a transverse aperture with a cotter pin 98 therein. A washer 99 is interposed between the cotter pin 98 and the side wall 43.

Rotatably mounted on the shaft 90 are clutch cylinders 100, 102 and 104. Although these cylinders are shown, any number can be used. Taking clutch cylinder as an example, as shown in FIG. 8, such clutch cylinder is essentially a right cylinder having a central bore therein for receiving the shaft 90. Each cylinder has a first portion and a second portion, each forming approximately one half of the axial length thereto. The first portion is a right cylinder with a complete cylindrical outer surface 117. A series of spaced radical lugs 116 extend axially along the outer surface 117. Any number of lugs can be provided, eight being shown by way of example. The second portion is also essentially a right cylinder but has an outer surface formed by the intersection of a cylindrical surface and a planar surface or flat shoulder 105. The planar surface 105 is in the form of a chordal surface extending across the cylindrical surface 115. The cylindrical surface 115 is coextensive with the cylindrical surface 117.

An indicator wheel is mounted on each clutch cylinder, and in the illustrated embodiment, indicator wheels 106, 107 and 108 are mounted respectively upon clutch cylinders 100, 102 and 104. As shown in FIG. 8, indicator wheel 106 is a flat disc formed as a right cylinder having a length equal to the length of the first portion of the clutch cylinder 100. The wheel 106 has a central bore 109 with interior indentations in the form of axial grooves 112 corresponding to the lugs 116 on the clutch cylinder and engageable therewith as seen in FIGS. 4, 5, 6 and 8. On the outer circumference of each indicator cylinder are radially spaced exterior indentations in the form of axial grooves 113 which separate the outer circumference into sections. The interval between each indentation or groove can be numbered or color coded or provided with other indicia, i.e., letters, various tactile surfaces and the like.

As seen in FIG. 3, the compression spring 114 is mounted on the shaft 90 to bias the clutch cylinders 100, 102 and 104 toward the plate 94 by reacting between the end of the cylinder 100 and the inside of the side wall 43.

Mounted in container 40 between the shaft 90 and the rear wall 44 is an actuator plate 92 in the form of a substantially rectangular planar'plate, the details of which are seen in FIG. 7. Centrally located therein are three elongated rectangular slots 120, 121 and 122 through which pass an edge portion of the indicator wheels 106, 107 and 108 respectively. The actuator plate 92 has elongated rods 123 and 124 extending from its sides at one end thereof for the purpose of pivotally mounting the plate. The rod 123 has a circular stop 125 midway along its length and a circular stop 126 at its outer end. Between these two stops the rod 123 will lie in and be supported rotatably in aperture 83 in the wall 43. The stops will prevent any lateral movement of rod 123. Stop 126 has a slot 142 in the the end surface to engage a key as will be explained hereinafter. Similarly rod 124 has a pair of spaced stops 127 and 128 mounted thereon and between these stops, the rod 124 will be rotatably supported in the aperture 87 in support wall 95. The rod 124 continues beyond the stops and is attached to a rod 129 perpendicular thereto, the rod 129 havng a plate 130 at its end. The plate 130 is normally interposed between the end of the shaft portion 91 and the central aperture 75 in the side wall 46, as shown in FIGS. 2 and 3 preventing the change of the combination except when the correct combination is set. At one end corner of the actuator plate 92, as seen in FIG. 7, there is an integral extension 131, oblique to the plane of plate 92:, forming a cam surface. The thickness of the extension is substantially the same as the actuator plate thickness.

The actuator plate 92 is spring biased toward shaft 90 into engagement with the circumference of each clutch cylinder by a compression spring which is rigidly connected in a suitable manner to the rear wall 44 and to the actuator plate 92 as seen in FIG. 4. The spring 140 is preferably located to left of the indicator cylinder 100 as viewed in FIG. 2. Mounted on the actuator plate 92 in a suitable manner are three spring fingers 145, preferably formed of spring steel. One end of each spring finger 145 is mounted rigidly to the actuator plate 92 as shown in FIG. 7. The other end of each spring finger 145 freely engages in one of the indentations 113 of the indicator wheel, as shown in FIG. 4.

The cover member 60 consists of four walls, namely, a front wall 150, a bottom wall 160, a top wall 170 and an end wall 180. The front wall 150 has four elongated centrally located rectangular slots 152, 154, 156 and 158 therein, as shown in FIG. 2. Projections 62 shown in FIG. 1 are formed at one end of the front wall 150.

The top and bottom walls 160 and 170 of the cover member have connected therebeneath two T-shaped elongated rods 161 and 171, respectively, which are slidably engaged within the slots 71 and 72, in the top and bottom walls 41 and 45 of the container 40, as shown in FIG. 4. The corresponding inverted T-shaped slots in the side wall 43 permit passage of the rods 161 and 171 therethrough.

Side wall 180 has a circular aperture 181 as seen in FIG. 2 for the reception of an auxiliary lock 208. On the inside portion of wall 180 are two threaded cylindrical blind bores 182 and 184 for the reception of pins 186 and 188, which as shown in FIG. 3, pass respectively through apertures 77 and 78 in the container side wall 43 and terminate at enlarged heads 189 and 190.

As seen in FIGS. 1-3, the cover member 60 is slidably mounted on the container 40. The front wall 150 of the cover member carries a slotted arm 200 which extends from a plate 201 attached by screws 203 to the front wall 150, as shown in FIGS. 4-7. Slotted arm 200 passes through a slot 50 inthe container front wall 42 and the free end of the slotted arm 200 is located between extension 131 and indicator cylinder 106. Arm 200 has two slots on one edge 205 thereof. Slot 202 is located near the bottom of arm 200 and slot 204 is located substantially midway on the arm. Both slots face towards the shaft 90. The width of each slot is slightly greater than the width of the extension 131. As shown, the edge 205 of the arm is curved or inclined somewhat at its inner end and the slot 202 is generally perpendicular to the edge 205. Thus, the slot 202 is disposed at a slight angle to the stot 204. This is to allow the cam extension 131 to be aligned with each slot respectively when the actuator plate upon which the extension 131 is mounted is caused to rotate by means of the correct combination being dialed or the key being used to open the lock. A spring 206 is fixedly connected between the cover member side wall 180 and the container side wall 43 to spring bias cover member 60 away from container 40. The cover member 60 is prevented normally from moving under the influence of the spring 206 due to the fact that the arm 200 abuts against the extension 131 on the actuator plate 92.

Mounted, in aperture 181 is anauxiliary lock 208. Key 209 which can open the lock 208 carries at its end an extension 210 which can engage the slot 142 inslotted head 126 on the rod 123. v I

As viewed in FIG. 2, the device is in a locked position with projections 62 engaged in clamps 63 on the receiver 64. Cover member 60 covers the indicator cyl-' inders 100, 102 and 104 so that the wheels 106, 107 and 108, and the indicia thereon, are not visible. To open the lock, the cover plate 60 is first pushed towards receiver 64 so that the cover member side wall 180 is adjacent the container side wall 43. This will cause the slots 152, 154 and 156 in the cover member front wall 150' to coincide with slots 56, 57 and 58 in the container front wall 42, thus exposing the indicator wheels 106, 107 and 108 to view. The indicator wheels are then rotated to the correct combination. This rotation of the wheels 106, 107 and 108 will also cause a rotation of the clutch cylinders 100, 102 and 104 due to the engagement of the grooves 112 with the lugs 116. The indicator wheel andclutch cylinders are so arranged that the planar surfaces 105 in the clutch cylinders 100, 102 and 104 will all align and face the actuator plate 92 when the correct combination is dialed, asseen in FIG. 5. Due to the reduced diameter presented by the planar surfaces 105, the actuator plate 92 will pivot towards the shaft 90 under the action of the spring 140 and the front portion of the extension 131 will become aligned with slot 204 in the arm 200 asshown in FIG. 5. The cover member side wall 180 is then released from its position adjacent the wall 43.

As previously indicated, the cover member 60 is normally prevented from moving under the urging of the spring 206 becausethe arm 200 abuts against the extension 131 onvthe actuator plate 92. However, when the cylinders have been moved to the unlocked position of FIG. ,5, the extension 131 aligns with the slot 204 in the arm 200 and the biasing force of the spring 206 pushes the cover member to the left as shown in FIG. 9. This movement will allow projections 62 to become disengaged from the clamps 63 or the receiver 64 and hence opens the lock. Also, as the cover member 60 moves to open the lock, the walls of the slot 204 slide along the extension 131 on the actuator plate 92. Due to the fact that the extension 131 is obliquely oriented to the planar surface of the actuator plate 92, a camming action will occur as such sliding takes place. This camming action will cause the actuator plate to pivot to the right as shown in FIG. 6. FIG. 10 shows in detail the camming action of the slot 204 onthe actuator plate 92 as it moves across theextension 131. The slot-204, located in the depending arm 200, moves in a straight line as indicated in FIG. 10 by the imaginary movement of thecover member 60 under the influence line 207. This movement is in a straight line because the depending arm 200 is rigidly connectedto the covermember 60 which is in turn connected to the container 40 by the T'-shaped rods 171 and 161. In- FIG. 10A the relationship of the slot204 and the extension 131 is the same as shown in FIG. 5. As showntherein, the correct combination has been dialedv and the slot 204 and the extension 131 become aligned due to the reduced-diameter provided by the planar surfaces 105.

which now abut the actuator plate 92. In FIG. 10B the depending arm 200is moving to the left due to the of compression spring 206. Because the camming extension 131 is oblique to the slot'204 and the planar surface'of the actuator'plate 92, the extension 131 and thus the actuator plate 92 .will be forced downwardly as shown in. FIG. 10B. This downward niovement is complete as seen in FIG. 6 and 10Cwhen the extension 1 31 has reached the end of the slot 204. Since the end of j actuator plate and spin the indicator cylinders in a random fashion. The enlarged heads 189, 190 at the ends of the rods 186 and 188 will prevent the cover member from moving completely off the container 40 by engaging the container side wall 43. This will also prevent the slot 204 from moving completely off the extension 131.

A key 209 can also be used to open the lock, as shown in FIG. 2. The key 209 is placed in auxiliary lock 208 and has an extension 210 fitting into the slot 142 in head 126 of rod 123. Turning of the key will rotate rod 123 and hence the actuator plate 92 to a position as shown in phantom in FIG. 4 wherein the slot 202 in the arm 200 will coincide with the extension 131. The cover member 60 will then move the arm 200 so that the slot 202 slides across the extension 131 under the bias of spring 206 to open the lock.

In the open position, with the correct initial combination dialed, the combination can be reset. In the open position slots 56, 57 and 58 in the container front wall 42 coincide with slots 154, 156 and 158 in the cover plate front wall 150. The indicator cylinders lying in slots 56,57 and 58 will thus be exposed to view. In this open position plate 130 mounted on rod 129 of the actuator plate 92 will have been rotated with the actuator plate 92 so as to allow a clear passage to the enlarged diameter portion 91 of the shaft 90 through aperture 75 in the side wall 46, as shown in FIG. 9. A tool or implement can be inserted through the aperture 75 to push against the shaft 90 to cause it to be moved to the left against spring 114. The enlarged diameter portion 91 of the shaft 90 will engage the right side of the clutch cylinder 104 and push all of the clutch cylinders 100, 102 and 104 to the left. Since indicator wheels 106, 107 and 108 are received in slots 120, 121 and 122 of the actuator plate 92, they will not move with the clutch cylinders. The clutch cylinders will be moved so as to have the lugs 116 move out of engagement with interior indentations or grooves 112, allowing the indicator wheels to be freely rotated on the portion of the clutch cylinders free of lugs, to any given number of color on their circumferences providing any combination desired. The shaft 90 is then released, allowing the springll4 to push the clutch cylinders back into engagement with the indicator wheels.

While one advantageous embodiment has been chosen to illustrate the invention it will be understood by those skilled in the art that various changes and modifications can be made therein without departing from the scope of the invention as defined in the appended claims. For example, the projections on the cover member could be bent around towards the container for entrance into the container. Thus providing a portable, self-contained padlock of the combination type.

We claim:

1. In a combination lock, the improvement which means operative when said members have been manipulated to said predetermined combination position to thereby move said latch means to said unlocked position and to simultaneously move said members out of their combination position so that the combination cannot be visually observed after the lock is unlocked.

2. The improvement according to claim 1 wherein said means includes a first means for moving said latch means and a second means for moving said members out of their combination position.

3. The improvement according to claim 2 wherein said second means includes a rotatably mounted actuator plate, and

means for rotating said actuator plate on setting of the predetermined combination.

4. The improvement according to claim 3 and further including spring fingers mounted on said actuator plate for engaging said members.

5. The improvement according to claim 4 wherein said means for rotating said actuator plate includes a cam means mounted on said actuator plate, and

a cam follower mounted on said latch means wherein said first means moves said cam follower along said cam means. 6. The improvement according to claim 5 wherein said first means includes 7 biasing means for moving said latch means when said cam means and said cam follower are aligned, and

wherein said cam means and said ,cam follower are aligned by manipulating said digitally operable members to said predetermined combination position.

7. The improvement according to claim 3 wherein said mounting means for said digitally operably members includes a shaft,

clutch cylinders rotatably mounted on said shaft, and

wherein said second means further includes means biasing said actuator plate towards said shaft.

8. The improvement according to claim 1 wherein said latch means covers said members when said lock is in the locked position by maintaining said aperture means out of alignment with said members.

9. The improvement according to claim 7 wherein said actuator plate includes a plate movable to allow the shaft to be manipulated for changing the predetermined combination to another predetermined combination but only when the correct combination is set.

10. A combination lock comprising:

a container with slots centrally located in one wall thereof;

a shaft rotatably mounted within said container;

clutch cylinders rotatably mounted on said shaft;

digitally operable indicator 7 cylinders containing combination indicia on their peripheries, said indicator cylinders being mounted on said clutch cylinders for observation through said slots and for manipulation to the correct combination;

an actuator plate mounted in said container and spring biased against said clutch cylinders, said actuator plate having slots therein for receiving portions of said indicator cylinders;

a cover plate movable along said container to open combination; and

and close the lock; means for moving said indicator cylinders from the means for moving said cover plate upon digitally macorrect combination on opening of the lock.

nipulating said indicator cylinders to the correct 

1. In a combination lock, the improvement which comprises: digitally operable members which can be manipulated to a predetermined combination position which will unlock the lock; mounting means for said digitally operable members; latch means movable relatively to said mounting means between a locked position and an unlocked position; aperture means in said latch means to permit digital manipulation of said members; and means operative when said members have been manipulated to said predetermined combination position to thereby move said latch means to said unlocked position and to simultaneously move said members out of their combination position so that the combination cannot be visually observed after the lock is unlocked.
 2. The improvement according to claim 1 wherein said means includes a first means for moving said latch means and a second means for moving said members out of their combination position.
 3. The improvement according to claim 2 wherein said second means includes a rotatably mounted actuator plate, and means for rotating said actuator plate on setting of the predetermined combination.
 4. The improvement according to claim 3 and further including spring fingers mounted on said actuator plate for engaging said members.
 5. The improvement according to claim 4 wherein said means for rotating said actuator plate includes a cam means mounted on said actuator plate, and a cam follower mounted on said latch means wherein said first means moves said cam follower along said cam means.
 6. The improvement according to claim 5 wherein said first means includes biasing means for moving said latch means when said cam means and said cam follower are aligned, and wherein said cam means and said cam follower are aligned by manipulating said digitally operable members to said predetermined combination position.
 7. The improvement according to claim 3 wherein said mounting means for said digitally operably members includes a shaft, clutch cylinders rotatably mounted on said shaft, and wherein said second means further includes means biasing said actuator plate towards said shaft.
 8. The improvement according to claim 1 wherein said latch means covers said members when said lock is in the locked position by maintaining said aperture means out of alignment with said members.
 9. The improvement according to claim 7 wherein said actuator plate includes a plate movable to allow the shaft to be manipulated for changing the predetermined combination to another predetermined combination but only when the correct combination is set.
 10. A combination lock comprising: a container with slots centrally located in one wall thereof; a shaft rotatably mounted within said container; clutch cylinders rotatably mounted on said shaft; digitally operable indicator cylinders containing combination indicia on their peripheries, said indicator cylinders being mounted on said clutch cylinders for observation through said slots and for manipulation to the correct combination; an actuator plate mounted in said container and spring biased against said clutch cylinders, said actuator plate having slots therein for receiving portions of said indicator cylinders; a cover plate movable along said container to open and close the lock; means for moving said cover plate upon digitally manipulating said indicator cylinders to the correct combination; and means for moving said indicator cylinders from the correct combination on opening of the lock. 